TIL there's no English word for "to speak among Esperantists in a language besides Esperanto", although I'm not sure one is needed either.
s/Esperantists/English-speakers/ and "non-English"
AFAIK, the English language is very verbose. If there are so many words, many of which have very similar meaning to others, then many of those words are not needed? Should be removed, even, until everyone forgets them and doesn't miss them at all?
"Very similar" is not the same as "identical". Having multiple words with similar, but not identical, meanings allows you to express more detailed nuances and shades of meaning.
> Should be removed
Language is an emergent social phenomenon, not something anyone really controls or directs, so what “should” be done with it is a bit meaningless.